[Source] Flexible ring mandrel

Hello out there,

Does anyone know of a source for flexible ring mandrels? (rubber,
for out of round rings)?


To make a flexible ring mandrel, coil a piece of printer paper
around a mandrel. Tape it so that it won’t come uncoiled. You can
now slide it off the mandrel and mark sizes on it using ring sizers.
It will work fine.

Tom Arnold

Not exactly sure what you mean but maybe make one from


The one I saw was commercially made but never took off. It was made
of Blue foam. It was not solid but was like a tapered hollow tube.
the numbers molded into it and looked pretty good.

I am sure there probably are some of these out there in the market.

Kenneth Singh

We will take a section of a file folder (light cardboard) and roll
it into a cone shape like a mandrel and tape it on the seams. Then we
pull ring sizers down it and mark the sizes. You can then pull any
funky shaped ring down it and check the finger size. Cheap and easy.


Many of us have been wishing we’d bought one of those when they were
still made. As far as I know, they are no longer being produced, but
we’re waiting and hoping someone will take up the challenge or locate
a lost stash of them somewhere.

David L. Huffman

If I was going to make one this is how I might do it…

Using investment make a negative mold of a good steel mandrel. Might
be good to lubricate the mandrel first. Might be good to use a smooth
polished mandrel without the size markings. You could mark sizes
after the fact, might be more accurate that way.

After complete curing pour in a suitable material such as the goop
they sell for coating tool handles, might take some experimentation
to find the right substance and the right finished thickness. Pour
out excess material because you don’t want a solid plug. Build up the
thickness in several coats. You could pull the new mandrel after the
first coat or two and then you could test the results as you go.

I might fool around with flexible foam window and door insulation,
the kind that comes in an aerosol can. That might help resiliency.
Squirt some in after you’ve made a hollow mandrel.

Just a thought.

I was told there were fabric mandrels filled with sand. That sounds
like an easy solution. I’ll share the pattern if I find myself
getting that creative.


I sometimes make a paper mandrel by wrapping a piece of 8.5x11 copy
paper around a standard mandrel, nice and tight, and taping it shut.
Slip it off the mandrel and you’ve got yourself a mandrel-shaped
tube. Now, take a ring gauge and a pen (ultra-fine Sharpie works
great) and slide each size onto the paper mandrel until it stops,
marking the point on the paper using the pen. When you’re finished,
you can go back and enlarge the lines to make viewing a bit easier.
Voila, flexible mandrel!

Cheap, too!

Hello Orchidland,

Brian Beiriger gave a very good, simple tip for creating a flexible
mandrel by wrapping paper around a standard mandrel, taping it
closed, then marking sizes by sliding on ring gauges and tracing the
stopping point with a Sharpie.

May I offer a way to create a more durable flexible mandrel. Use a
sheet of transparency film. Wrap and trim the film so that it barely
overlaps; tape closed with a strip of transparent tape; then make
your marks as noted by Brian.

This should hold up well for a long time.

Judy in Kansas, where the day temps are lovely (mid 70s) and the
nights are even chilly enough for a light blanket. Love not having
to use the A/C and paying for the power!!

I have made these paper wrapped flexible mandrels and they work ok.
but they are nowhere near as good as the old rubber, hollow,
graduated flexible mandrel I had at one shop I worked in years ago.
I think it might have come from Gesswein but it was long ago and I
have searched without success for one ever since. Are there any tool
making company folks out there who can get their company to make
these again. People will buy them.


I have used a flexible mandrel before, years ago. It was like a
stiff foam mandrel covered in a plastic with sizing lines on it. I
know it’s out there but I can’t remember the source. I’ll do more
research and get back.

Steve Cowan
Arista Designs

I still have my flexible mandrel and I got it from Rio at least a
couple of decades ago.


I have one I bought 4 or 5 years ago but I can’t remember where I
got it… It is stamped Keener Enterprises, USA and has a patent
number printed on it.

Donna in VA